1. Field of the Invention
The present invention relates to an imaging apparatus, and more particularly to exposure control of the imaging apparatus at the time of flash photography.
2. Description of the Related Art
Some of conventional imaging apparatuses perform automatic exposure control so that a subject is properly exposed and, when an exposure time necessary to achieve proper exposure is longer than a predetermined exposure time, perform flash photography. Such an imaging apparatus controls the minimum exposure time at the time of flash photography so as to be equal to or longer than the longest light emission time, a time period during which flash light may possibly be emitted, so that exposure is not ended during flash light emission.
For example, Japanese Patent Application Laid-Open No. 2003-43550 discusses a camera system which changes the minimum exposure time at the time of flash photography according to the longest light emission time of an electronic flash device connected to a camera in consideration that the longest light emission time differs for each type of electronic flash device connected to the camera.
However, with conventional imaging apparatuses which set the minimum exposure time at the time of flash light emission according to the longest light emission time of the electronic flash device, there has been the following subjects. For example, with a scene having a bright background and a dark main subject such as a backlight scene in the daytime, an attempt to properly expose a main subject by emitting flash light prolongs the exposure time exceeding an exposure time for achieving proper background exposure. Therefore, there has been a problem of background overexposure.
Further, when an aperture is changed to a lower exposure amount level corresponding to the prolonged exposure time to avoid background overexposure, a distance over which the flash light reaches is reduced due to the closed aperture and accordingly a sufficient amount of flash light does not reach the main subject. Therefore, there has been another problem that a dark image is captured for the main subject.